1. Field of the Invention
The present invention relates to a wireless communication apparatus and method in an image-forming system. More particularly, the present invention provides a plurality of Radio Frequency Identification (RFID) tags mounted on a plurality of units of the image-forming system, respectively, and an RFID reader mounted on a motherboard of the image-forming system that can read and write data from/into the RFID tags via wireless communication.
2. Description of the Related Art
Electrophotography is widely used in image-forming systems such as a copy machine, a Laser Beam Printer (LBP) and a laser fax. As well known in the art, electrophotography comprises process steps of electrification, exposure, development, transfer and fixing.
FIG. 1 schematically illustrates an engine mechanism of an image-forming system based upon a general electrophotography, in which contact electrification is utilized.
The contact electrification shown in FIG. 1 is adapted to minimize ozone generation induced from electrification, in which a conductive roll or brush used as a contact electrifier is contacted with a photosensitive drum to form a predetermined level of surface potential. In particular, FIG. 1 illustrates a contact electrification using a conductive roll.
As shown in FIG. 1, a photosensitive drum 10 is rotated in the direction of an arrow by an engine-driving motor (not shown), which is a main motor of an engine unit, in response to respective process steps of the electrophotography.
First, in an electrification step, the photosensitive drum 10 as a photosensitive body is electrified by an electrification roll 12 so that the photosensitive drum 10 can be uniformly charged. In this case, the electrification roll 12 is applied with negative potential under the negative charge voltage VCH.
The photosensitive roll 10 is electrified through its contact with the electrification roll 12 to have a negative surface potential, which is typically about −800V. Feed rolls 30 and 32 transport a sheet of printing paper 42 fed from a manual feed slot (not shown) toward a developing unit. Upstream of the feed rolls 30 and 32, there is mounted a manual feed sensor 40 for detecting the insertion of the printing sheet 42 into the manual feed slot. Downstream of the feed rolls 30 and 32, there is mounted a feed sensor 41 for detecting whether the sheet inserted through the manual feed slot is properly fed toward the developing unit.
In a second step of exposure, the electrified photosensitive drum 10 is exposed corresponding to a manuscript or an image data to form an electrostatic latent image on the photosensitive drum. The electrostatic latent image is formed on the photosensitive drum by exposing only a portion of the photosensitive drum 10 corresponding to an image area to be printed with a Laser Scanning Unit (LSU) 14. That is, the exposed portion of the drum 10 changes its surface potential while the remaining portion of the drum 10 maintains the surface potential, and therefore a potential difference is induced between the exposed and remaining portions to form the electrostatic latent image.
In a third step of development, developing agent is applied onto the electrostatic latent image on the photosensitive drum 10 to convert the latent image into a visible image. That is, a developing roll 16 is typically supplied with a developing bias voltage of about −450V to have a negative potential, and the developing agent is applied on the developing roll 16. A doctor blade (not shown) is provided to regulate the developing agent applied on the developing roll 16 to a constant quantity. Then, the developing agent of the negative potential is partially moved to the exposed area of the photosensitive drum 10 and applied thereon under the potential difference to complete the developing step.
In a fourth step of transfer, the developing agent applied on the photosensitive drum 10 is transferred to the printing sheet by a transfer roll 18. The transfer roll 18 is generally supplied with a transfer voltage VT of about +800 to +1500V to fix the developing agent from the photosensitive drum 10 to the printing sheet which is being fed.
Fifth, in a fixing step, the transferred printing sheet is passed through a hot roll 20 of a high temperature and a pressure roll 22 of a high pressure to fuse toner on the printing sheet. Then, the fixed printing sheet is discharged out of the image-forming system to complete a copying or printing process on a single printing sheet.
In the image-forming system, a manual feed unit is devised to print special sheets individually since those special sheets (e.g., transparent sheets for an overhead projector (OHP), envelope or label) are not easily fed by a common feed cassette. Although a multi-purpose paper feed unit may be used for continuous printing of special sheets, low price image-forming systems generally use a manual feed unit which does not require additional devices.
The manual feed printing starts with gripping a single sheet with the feed rolls 30 and 32 to a predetermined degree. Then, the feed rolls 30 and 32 are driven in response to a printing command to feed the gripped sheet along a sheet feed direction.
When the sheet is inserted into the manual feed slot in a standby status, the manual feed sensor 40 shown in FIG. 1 detects the insertion of the sheet. A motor is driven in response to the detection of the sheet insertion to move the sheet to a predetermined distance so that the feed rolls 30 and 32 can grip the leading edge of the sheet to a predetermined degree as shown in FIG. 1 and load the sheet in position. In response to a printing command, the motor is driven again to turn the feed rolls 30 and 32 from the sheet-loading position so that the sheet can be fed and printed.
In the image-forming system as above, memories are mounted on fixing and developing units, respectively, so that a central processing unit (CPU) on the motherboard can analyze the cartridge information of the fixing and developing units.
In this case, a CPU writes desired information including provider name, model name, the number of printed pages, the number of printed dots and the lamp-on time of the fixing unit (e.g., a fixing unit comprising a hot roll 20 and pressure roll 22) into the memory mounted on the fixing unit, and reads information from the memory periodically or in response to user selection to analyze the present status of the fixing unit for example in order to inform replacement time to a user.
In addition, the CPU of the motherboard can write or read desired information including provider name, model name, serial number, the number of pages printed up to the present, the number of printed dots and the quantity of waste toner (e.g., the number of rotations of an Organic Photosensitive Conductor (OPC) unit) into/from the memory mounted on the developing unit (e.g., a developing unit comprising a developing roll 16) to analyze the present status of the developing unit in order to inform replacement time to the user.
However, since the motherboard is necessarily in direct contact with the memories in order to write/read the data into/from the memories, this disadvantageously increases design limitations of the image-forming system.